Human amnion epithelial cell (hAEC) and regulatory T cell (Treg) administration polarise macrophages toward and M2 state in
. (A) hAEC administration reduced CD86+ M1 macrophages in C57Bl6 mice but not in Rag 1
mice. M1 macrophages were significantly increased in the lungs of animals that received Tregs alone, non-Tregs alone, and non-Tregs + hAECs (**P <0.01), but this was not observed in animals that received Tregs + hAECs. (B) CD206+ M2 macrophages were significantly increased in Rag 1
-/- animals that received Tregs + hAECs (**P <0.01) and, to a lesser extent, non-Tregs + hAECs (*P <0.05). This trend was similar to that seen in C57Bl6 mice, in which hAEC treatment significantly increased CD206+ macrophages in the lungs (****P <0.0001). (C) Representative image of CD86+ and CD206+ macrophages between groups with adoptively transferred cells (scale bar = 200 μm, DAPI, blue; F4/80, green; CD86, pink; CD206, white). These findings were supported by similar changes to the M1- and M2-specific gene expression. (D) Co-administration of Tregs and hAECs significantly increased transcription of M2-specific genes found in inflammatory zone protein-1 (FIZZ-1) and Ym-1 (P <0.05) (*p<0.05, ****p<0.0001). (E) Adoptive transfer of Tregs to Rag1
-/- mice significantly reduced phagocytic activity of lung macrophages (*P <0.05); however, increased phagocytic activity was observed in macrophages from Treg + hAEC animals compared with Tregs alone (**P <0.001). hAEC priming of macrophages did not alter FoxP3 transcription when the macrophages were co-cultured with CD4+ cells. (F) CD4+ cells were cultured with transforming growth factor-beta (TGFβ) (5 ng/mL) as a positive control. DAPI, 4′,6-diamidino-2-phenylindole.